I've never seen any casual guest at the Shard (and at the Gherkin for that matter) not being searched. Those who work there obviously go through the main entrance with their building pass, but they've been vetted when they were issued with said building pass and I´m cool with that. As is anyone else.

PS your location is "UK"? Really? Because I´m surprised at your reaction, given that there´s not very many countries, certainly not in Europe, where security is as tight as in the UK and has been for decades (remember the "Troubles" and the "Ring of Steel" in the City?).